Sending packets at great distances

Lynks · Post by **Lynks** » November 15, 2004, 12:21 pm

Anyone know a way to send ethernet transmission over a great distance (4 km down a mine, then 6km across at every Km)? Basically, we want to avoid using repeaters. I know there is a theory that says the slower your transmission speed, the further the data can travel.

Zaelath · Post by **Zaelath** » November 15, 2004, 12:32 pm

Fibre optics

You're not going to get cat 5 running 4km.

There's a difference between needing perfect termination of a cat 5 cable to get it to operate at 100Mbit over 100 metres instead of 10Mbit, and attempting to run 4km lines.

Perhaps some type of crappy modem connection over POTS cabling would be possible.. (analog signals don't suffer the same level of attenuation issues digital does)

Aabidano · Post by **Aabidano** » November 15, 2004, 1:06 pm

What are you trying to do and how much are you willing to spend? Signal timing issues are going to rule out ethernet even with repeaters.

You could do a 1km segment (best case) with fiber. You'd only be able to repeat it once taking you out to 2km.

Tenuvil · Post by **Tenuvil** » November 15, 2004, 1:08 pm

either fiber or copper with beefy CSU/DSU on either end

Lynks · Post by **Lynks** » November 15, 2004, 2:15 pm

Its not really for me but a customer. They are so fussy when it comes to this stuff. They said they don't want to install fiber optics, and want to use cat 5 ethernet cable.

I told them they will only get 100-200 meters max but they aren't listening. We're just going to tell them to fuck off or ditch the ethernet thing I think.

PS. Why are mines so cheap when it comes to this stuff, they pull in billions annually.

And thanks for the suggestions

Aabidano · Post by **Aabidano** » November 15, 2004, 2:23 pm

I asked one of our transmission guys, he says you can go out to ~18,000 feet on a 4 pair 22 gauge line before you have to put in a repeater. It's mainly a matter of the wire size, once the attenuation hits ~48db they have to insert a repeater.

Lynks · Post by **Lynks** » November 15, 2004, 4:26 pm

Aabidano wrote:I asked one of our transmission guys, he says you can go out to ~18,000 feet on a 4 pair 22 gauge line before you have to put in a repeater. It's mainly a matter of the wire size, once the attenuation hits ~48db they have to insert a repeater.

Cool, thanks. I'll add that to the options we are giving them.

Lynks · Post by **Lynks** » November 15, 2004, 4:46 pm

Cisco offers some long reach ethernet thing. Goes up to 5000 feet before you need a repeater for a good price.

Tenuvil · Post by **Tenuvil** » November 15, 2004, 5:15 pm

Lynks wrote:PS. Why are mines so cheap when it comes to this stuff, they pull in billions annually.

Just curious, why do they need networking that far below the earth? Are they doing some sort of monitoring via network? Or are people wanting to surf the web in a mineshaft?

Lynks · Post by **Lynks** » November 15, 2004, 5:58 pm

They have systems that detects air quality (what we do/sell). So our main product measures air current and the way they receive that information is by calculation the 4-20 (current output). They (the mines) have a ton of other information as well that they receive such as CO and CO2 levels, temperature, ect, by other products.

Basically, they want to add our product to their existing ones on the same line, which is possible,

Bubba Grizz · Post by **Bubba Grizz** » November 15, 2004, 10:28 pm

Tenuvil wrote:
Lynks wrote:PS. Why are mines so cheap when it comes to this stuff, they pull in billions annually.
Just curious, why do they need networking that far below the earth? Are they doing some sort of monitoring via network? Or are people wanting to surf the web in a mineshaft?

Are you kidding? They are Raiding and they need the feel of the cave before they can really get into it. It is also the only place their wives won't bitch at them or catch them with internet porn.

noel · Post by **noel** » November 15, 2004, 11:08 pm

I'm also curious. Why don't they want to use fiber?

Lynks · Post by **Lynks** » November 15, 2004, 11:53 pm

noel wrote:I'm also curious. Why don't they want to use fiber?

I'm not 100% sure, but from what I hear, it would cost millions to upgrade a mine's system and cause them a few days dowtime, costing them a few more million.

I don't know why they wouldn't though, they can easily afford it, but it would mean that 1000+ workers wouldn't get nice X-mas bonuses.

Edit: Also, they are waiting for the next big jump in underground wireless. A professor in Sudbury, Dr. Banting (i think thats how you spell it), is on the edge of perfecting it. He was able to run the major activities of a mine 400 KM away using his wireless technology.

Aabidano · Post by **Aabidano** » November 16, 2004, 8:04 am

If you've got to pull cable, it might as well be fiber. It's much more flexible than copper.

If you've got straight shots and it isn't critical stuff you could use off the shelf wireless and pringles can antenae

noel · Post by **noel** » November 16, 2004, 4:17 pm

Lynks wrote:
noel wrote:I'm also curious. Why don't they want to use fiber?
I'm not 100% sure, but from what I hear, it would cost millions to upgrade a mine's system and cause them a few days dowtime, costing them a few more million.

That's really odd. I'd think they could use existing cable trays, and just drop the fiber down the mine. I guess if they have lots of mines, it could cost millions, but fiber isn't that expensive anymore... The networking equipment on either side would be a bit more though... I'm also curious how they're getting an Ethernet signal of any kind down the mine on CAT5.

Edit: Also, they are waiting for the next big jump in underground wireless. A professor in Sudbury, Dr. Banting (i think thats how you spell it), is on the edge of perfecting it. He was able to run the major activities of a mine 400 KM away using his wireless technology.

That's pretty sweet. I was actually thinking of a wireless device when I saw this post yesterday, but you'd need line-of-sight, and I assumed that would have already been thought of.

Voronwë · Post by **Voronwë** » November 16, 2004, 5:36 pm

point a giant electron beam down there. tweak the quarks in the electrons or some shit and teleport the data there.

just make sure that nobody fucking touches the beam. should save some money on best control as well.

archeiron · Post by **archeiron** » November 16, 2004, 7:05 pm

Voronwë wrote:point a giant electron beam down there. tweak the quarks in the electrons or some shit and teleport the data there.

just make sure that nobody fucking touches the beam. should save some money on best control as well.

Why use that when you could have a really long ticker tape?

Voronwë · Post by **Voronwë** » November 16, 2004, 7:26 pm

what is bps throughput of ticker tape?

Vaemas · Post by **Vaemas** » November 17, 2004, 12:06 am

I'm thinking string and tin cans.